As Mr. Obama said, the “privilege to witness history taking place” did not change the fact that “many questions remain unanswered.” The questions that floated just beneath the euphoria included: whether the authoritarian regime was indeed over, how a country of weak political institutions and few opposition leaders would organize a transition, and whether Egypt could both transform itself and remain a stable force in the region.

“This has got a long way to play out,” says Richard Haass, president of the Council on Foreign Relations (CFR) in New York. Using the analogy of a baseball game, Mr. Haass said Thursday that Egypt was “squarely in the bottom of the second inning” – and that Mr. Mubarak’s resignation, as significant as it would be, would still advance Egypt only “to the third inning.”

As unimaginable as Mubarak’s resignation might have seemed just three weeks ago, many foreign-policy analysts are echoing Haass’s words with the perspective that the hard part of Egypt’s transition is still to come.

Saying “what Egypt needs is a full reboot of its political system,” Mr. Katulis lists constitutional reforms and a new round of “free and fair parliamentary elections” as two essential steps in the months ahead.

But before that can happen, the question of Egypt’s transitional leadership looms. “It remains unclear whether the Egyptian people will accept Vice President [Omar] Suleiman as an interim leader,” he says.

And then there is the role of the military. Egyptians were showering accolades on the soldiers in their midst Friday, but in the post-euphoric days ahead, how will the people respond to the reality that the country’s Supreme Military Council has taken control of the state’s affairs?

In his remarks Friday, Obama quoted Martin Luther King Jr. in saying, “There is something in the soul that cries out for freedom,” and he lauded in particular Egyptian youths. His remarks brought out several themes that the president has emphasized since the beginning of the crisis: Political reform must be inclusive and “bring all of Egypt’s voices to the table,” it must continue to be nonviolent, and it must respond to the “boundless aspirations” of Egyptian youths.

This suggests that the administration is sticking by the “core principles” that Vice President Joe Biden elaborated to Mr. Suleiman earlier this week: that there must be no recourse to violence by anyone and no suppressive actions by the government in the transition period; that the Egyptian people must be able to exercise their universal rights, including assembly and expression, and democratic rights including the freedom to choose their civilian leaders; and that the political reform must be “meaningful, lasting, and immediate,” in the words of the White House.

To accomplish that, the Obama administration has demanded that Egypt’s emergency law be rescinded immediately, to allow for the legal assembly and political organizing that will be necessary if robust and representative political parties are to spring up.

The crux of Obama’s words was remarkably close to the reaction from European leaders in Brussels – suggesting that the United States and the Europeans have been in close contact on how best to present pressure for change without coming across as imposing their views.

The European Union said in a statement that “an orderly and irreversible transition towards democracy and free and fair elections is the shared objective of both the EU and the Egyptian people.” Egypt’s political dialogue must now be “accelerated, leading to a broad-based civilian government which will respect the aspirations of, and deliver stability for, the Egyptian people,” the statement said.

America’s close relations with the Egyptian military will be crucial as the transition process moves forward, European officials in Washington said – especially given the big (though as yet unclear) role the military will be playing in Egyptian affairs. Obama singled out the military, saying it had served “patriotically and responsibly” during the protests and would now have to “ensure a transition that is legitimate in the eyes of the Egyptian people.”

The days ahead, says Haass of CFR, will be tricky and will require that Egypt’s interim powers offer genuine signs of forward movement, even as the Egyptian people refrain from demanding that things change too fast. “You’ve got to avoid the two extremes of chaos,” he says – “too much too soon” on the one hand, “but also stasis, or just standing still.”

Some Egyptians were already expressing a cautious view on how quickly the political transition would occur, with opposition leader Mohamed ElBaradei saying it could take a year to prepare for elections.

One thing to watch for in terms of the military in the days ahead, Haass says, is the extent to which it is able to play its interim role without slipping into politics. “The more [the Army] becomes a political actor, the more it loses some of its above-politics legitimacy,” he says. If the military loses that legitimacy, he adds, Egypt risks losing a key institution for its transition process.